螺旋摆动液压缸间隙的优化设计

Optimal design for screw rotary cylinder's radial clearance

为获得螺旋摆动液压缸的润滑特性,在分析其结构和工作原理的基础上,设计7种不同径向间隙的螺旋副,使用Pro/E软件建立螺旋摆动液压缸内部流动油膜数学模型;利用Gambit 2.3.16进行结构化六面体/楔形网格划分后导入Fluent 6.3.26中,采用层流模型和SIMPLE算法,对不同径向间隙螺旋副内油膜三维流场和同一间隙不同偏心距下的螺旋流动特性进行模拟,得到螺旋副内部压力场以及承载力、刚度、最高温度、流量与间隙之间的关系。研究结果表明:螺旋副在径向间隙为0.10 mm时性能最佳;为获得较大的承载性能,同一半径间隙,制造条件允许且能形成流体动压润滑条件下应选择较大的偏心距;当缸体和空心螺杆的表面粗糙度分别为3.2μm和1.6μm,最小膜厚大于9μm时,能够形成良好的流体动力润滑。

In order to obtain the lubricating capability of screw rotary cylinder,structural design and operation principle were introduced.Seven screw pairs with different radial clearances were designed.The models were built by three-dimensional software Pro/E.Structure mesh was generated by using Gambit 2.3.16.Based on laminar flow model and SIMPLE algorithm,the interior flow fields in different radial clearances and the same clearance at different eccentricities were numerically simulated and analyzed with Fluent 6.3.26.The relationships of dynamic pressure distribution,force,stiffness,maximum temperature,flow rate and radial clearance were obtained.Simulation results show that the performance of oil lubricated screw pair is the best at the clearance of 0.10 mm;At the same radial clearance,greater eccentricity can obtain heavy bearing capacity and hydrodynamic lubrication;When the surface roughness of cylinder body and hollow screw are respectively 3.2 μm and 1.6 μm,in addition,minimal film thickness is more than 9 μm,and good hydrodynamic lubrication is formed.